Damper system for hot gas drying oven



March 1967 A. F. CAFIERO ETAL 0 DAMPER SYSTEM FOR HOT GAS, DRYING OVEN Filed March 24, 1965 la 'FIG.I

, FIG 4d I N VEN TOR-5 ANTHONY F. CAFiERU BRTHUR VlTAGLlANO ATI RNEY United States Patent 3,307,273 DAMPER SYSTEM FOR HOT GAS DRYING OVEN Anthony F. Cafiero, Fairfield, and Arthur Vitagliano, Hawthorne, N.J., assignors to A. F. Cafiero & Co., Caidwell Township, N.J., a corporation of New Jersey Filed Mar. 24, 1965, Ser. No. 442,443

Claims. (Cl. 34225) This invention relates to a damper system for hot gas drying ovens, such as ovens fired by gas, infra red coils, oil, steam, and the like, and employing hot gas as the drying medium. More specifically, it deals with specially-controllable vents in the floor of the hot gas supply chamber of such an oven, said vents being controlled as to area by means of angularly-positioned slides movable thereover, and with vents in the floor of the web line chamber, said latter vents being controlled as to area by hinged flaps disposed thereover.

The drying of coated webs is usually accomplished in an extended 3-chamber drying oven. The base material for the manufactured sheet, such as a layer of plastic foam, is deposited continuously on a continuous paper sheet which passes through the web line chamber of the oven. Other material such as the decorative upper coating is also deposited on the plastic layer, and the volatile material contained therein is driven from the plastic layer.

by a current of air and flue gas, adjusted to the proper temperature. When the dried plastic sheet reaches the end of the oven, it is peeled off the paper base, and the latter is returned to the oven as a continuous belt.

One of the greatest problems in such drying ovens is the proper distribution of the hot drying gases and the proper venting thereof. Since the web varies in'the thickness of deposited material and the drying gas varies in composition and temperature distribution during each run, it is highly desirable to be able to vary the amount of hot gas impinging upon a specific area in thedrier. Also, it is very desirable to alter, during each run, the gas discharge from the web line chamber to the recirculation and exhaust chamber. Various proposals have been made in the art to effect an improvement with respect to these requirements, but very little success has been achieved in these directions.

According to the present invention, a damping system has been devised which gives extraordinarily accurate and adequate control of the volume of impinging hot drying gases within the entire area of the drier, as well as excellent control of the discharge of such gases into the recirculation and exhaust chamber. The invention will be more readily understood by reference to the accompanying drawing in which a preferred embodiment is described, and in which FIGURE 1 depicts a cross sectional elevational front view of a half of a drier made in accordance with the present invention, it being understood that the remaining half of the oven, not depicted is similar to, and is an extension of, that shown in the figure. FIGURE 2 illustrates an enlarged elevational side view, taken along the plane of line 22 of FIGURE 1, and shows the portion of the supply chamber floor wherein is mounted the drying gas vent and area control damper therefor. FIGURE 3 presents an enlarged cross-sectional side view, taken along the plane of line 3-3 of FIGURE 1, and shows the portion of the web line chamber floor wherein is mounted the return-exhaust vent and the damper control therefor. FIGURES 4a to 4d illustrate enlarged plan views of the damper for controlling the drying gas vent in the supply chamber floor, as the movable slide is disposed in closed, partly open, and entirely open positions, respectively, while FIGURE 5 depicts a cross-sectional side view taken along the plane of line 5-5 of FIGURE 4a, showing the runner mounting for See the slide. The same numerals refer to similar parts in the various figures.

Referring again to the drawing, numeral 10 indicates generally one half of a drying oven having an outer shell 11, a top 12, and bottom 13. This oven is preferably made of metal, such as galvanized steel, and it is provided with a steel sheet floor 14, defining an upper hot gas supply chamber 15, and a lower metal sheet floor 16, defining a middle web line chamber 17. A lower recirculation and exhaust chamber 18 is defined by floor 16 and bottom 13. A gas burner (not shown) feeds hot gases into chamber 15, and temperature sensors and thermocouples are positioned throughout the chambers to indicate the temperature conditions existing therein.

Positioned at regular intervals along the length of floor 14, are elongated, generally-rectangular slots or vents 19 which, when entirely open, are designed to discharge all of the hot gases fed from a burner into chamber 15. These slots are provided, at their peripheries, with downwardly-directed lips or flanges 20 for the purpose of strengthening the'cut-ont area. Disposed over the slots 19, are wider slides 21, consisting of fiat sheets of metal having upwardly-directed peripheral lips or flanges 22 which serve to strengthen the slides and prevent them from warping. Slides 21 are in the shape of a parallelogram, the long sides of which are positioned at an angle of about 5-6 with respect to the sides of slots 19.

The ends of slides 21 are provided with projecting edges or lips 23 which are designed to slide under the upraised side 24 of angle iron 25, the lower side 26 of which is fastened onto floor 14 by screws 27. Thus, angle iron member 24 serves as a track guide for lip 23, and serves to position the slide 21 as it is moved horizontally. A flat boss 24 is attached to the upper surface of slide 21 at 45, by welding, or the like, and movably attached to the upper portion of boss 24 at pivot 26 is arm 47 which,

in turn is attached to arm 28 at pivot 29. The upper end of arm 28 is affixed to control rod 30. The latter is hungon mountings 31, and extends through side 11, and terminates with control handle 32. It is apparent that, by means of this handle, it is possible to slide plate 21 into a position as in FIGURE 4a, wherein the entire slot 19 is covered, or, as in FIGURE 4b, wherein the lower right hand portion of slot 19 is open, or, as in FIGURE 40, when the upper portion of slot 19 is open, or, as in FIG- URE 4d, where the entire slot 19 is open, or in any other intermediate position.

Mounted in spaced relation in floor 16 of web line chamber 17, and desirably in staggered relation with respect to slots 19, are elongated generally rectangular slots 33. These slots are desirably provided at their peripheries with a collar 34 which has a portion 34 projecting below floor 16, and portion 34" projecting above floor 16. Hingeably attached at 35 to one of the sides of collar 34" is damper flap 36 which covers slot 33 when it is in closed position. Attached to the hinged end of flap 36 is control rod 37 which leads out of wall 11 of oven 10, and terminates with control handle 38. Thus, it is seen that by turning handle 37 to a set position, it is possible to set flap 36 to a position, for example, as position 36', to control the rate of discharge of hot gases passing into recirculation-exhaust chamber 18, from where the gases may be completely or partially recycled by a blower (not shown), and, if desired, additional gas or air may be added thereto before the gases are returned to chamber 15. Web mountings 39 span chamber 17, and it is over these rod mountings that the web passes, as it is subjected to the drying operation, which consists of hot gases passing through controlled slots 19, then through controlled slots 33, and out through chamber 18 for exhaust and/ or recirculation.

We claim:

1. A damping system for a hot gas drying oven having a top, sides, bottom, and having a gas supply chamber superimposed over a web line chamber which, in turn is superimposed over a recirculation-exhaust chamber, comprising,

a gas supply chamber floor having a series of spaced laterally-elongated slots serving as discharge vents for hot gas,

a fiat plate angularly disposed over each of said slots and generally of parallelogram shape and having a width greater than that of each slot and adequate to cover the entire slot, when in closed position, and having track-engaging means on its ends,

a track disposed over and near each end of said slot and designed to engage said plate-engaging means and to permit sliding of said plate over said slot so as to open one side of said slot or the other side thereof or the entire slot, when in open position, whereby the amount of hot gas passing therethrough into a recirculation-exhaust chamber may be controlled with respect to the slot area, and hand control means connected to the top of said plate and extending out of the side of said oven for adjusting the position of said plate over said slot.

2. A damping system according to claim 1 in which the hand control means comprises a series of pivoted arms attached to the top of said plate, and a laterally-directed control rod attached to said arms and extending through the side of said oven and terminating with a control handle.

3. A damping system for a hot gas drying oven having a top, sides, bottom, and having a gas supply chamber superimposed over a web line chamber which, in turn, is superimposed over a recirculation-exhaust chamber, comprising,

a gas supply chamber floor having a series of spaced laterally-elongated slots serving as discharge vents for hot gas,

a flat plate angularly disposed over each of said slots and generally of parallelogram shape, and of width greater than that of each slot and adequate to cover the entire slot when in closed position, and having track-engaging means on its ends,

a track disposed, over and near each end of said slot and designed to engage said plate-engaging means and to permit sliding of said plate over said slot so as to open one side of said slot or the other side thereof or the entire slot, when in open position, whereby the amount of hot gas passing therethrough into a recirculation-exhaust chamber may be controlled with respect to the slot area,

hand control means connected to the top of said plate and extending out of the side of said oven for adjusting the position of said plate over said slot,

a web line chamber floor having a series of spaced laterally-elongated openings serving as discharge vents for hot gas,

a flap disposed over and hinged to one side of each of said openings serving to close said opening or to open it to any position, and

hand control means connected to the hinged end of said flap and extending out of the side of said oven for adjusting the position of said flap over said openmg.

4. A damping system, according to claim 3, in which each opening is lined with a substantially vertical continuous sleeve, and the flap is hinged onto the top of said sleeve.

5. A damping system, according to claim 3, in which the flap control means comprises a rod which extends out of the side of said oven, and a control handle serving as a terminus for said latter rod.

References Cited by the Examiner UNITED STATES PATENTS 1,793,086 2/1931 Hartford 34225 X 1 388,573 11/1932 Sadwith 34-225 1,942,828 1/1934- Parkes 34-225 2,161,211 6/1939 Werner 34-233 3,222,800 12/1965 Siegel et al. 34212 FREDERICK L. MATTESON, JR., Primary Examiner.

C. R. REMKE, Assistant Examiner. 

1. A DAMPING SYSTEM FOR A HOT GAS DRYING OVEN HAVING A TOP, SIDES, BOTTOM, AND HAVING A GAS SUPPLY CHAMBER SUPERIMPOSED OVER A WEB LINE CHAMBER WHICH, IN TURN IS SUPERIMPOSED OVER A RECIRCULATION-EXHAUST CHAMBER, COMPRISING, A GAS SUPPLY CHAMBER FLOOR HAVING A SERIES OF SPACED LATERALLY-ELONGATED SLOTS SERVING AS DISCHARGE VENTS FOR HOT GAS, A FLAT PLATE ANGULARLY DISPOSED OVER EACH OF SAID SLOTS AND GENERALLY OF PARALLELOGRAM SHAPE AND HAVING A WIDTH GREATER THAN THAT OF EACH SLOT AND ADEQUATE TO COVER THE ENTIRE SLOT, WHEN IN CLOSED POSITION, AND HAVING TRACK-ENGAGING MEANS ON ITS ENDS, A TRACK DISPOSED OVER AND NEAR EACH END OF SAID SLOT AND DESIGNED TO ENGAGE SAID PLATE-ENGAGING MEANS AND TO PERMIT SLIDING OF SAID PLATE OVER SAID SLOT SO AS TO OPEN ONE SIDE OF SAID SLOT OR THE OTHER SIDE THEREOF OR THE ENTIRE SLOT, WHEN IN OPEN POSITION, WHEREBY THE AMOUNT OF HOT GAS PASSING THERETHROUGH INTO A RECIRCULATION-EXHAUST CHAMBER MAY BE CONTROLLED WITH RESPECT TO THE SLOT AREA, AND HAND CONTROL MEANS CONNECTED TO THE TOP OF SAID PLATE AND EXTENDING OUT OF THE SIDE OF SAID OVEN FOR ADJUSTING THE POSITION OF SAID PLATE OVER SAID SLOT. 